Introd uction t o Databa se Confi guratio n 3-7
RFC1490 Format
An RFC1490 format used for SNA traffic is configured in the frame relay LLC2
Interface/Bridge Port record. The options, in order of lowest overhead to highest
overhead, are:
●Native LL C2 (als o known as BNN, or Bo undary N e twork No de). Whe n this
format is used, no MAC addresses are transmitted across the frame relay link.
●802.5 SR B (sourc e route b ri dge) (al so known as BAN, or Boundar y Acces s
Node. (SmartSwitch 1800 devices support BAN type 1). This format is gen-
erally used for 3174 gateways and AS/400s, because they need to see a MAC
address).
●802.3 TB (tran sparent bridg e), use d when ta lking t o router s that cannot d o BAN
or BNN.
Subscriber IDs
Subscriber IDs are only used locally within each SmartSwitch 1800 to link records
(e.g. SDLC PU record to LLC host record), unless the device is running X.25, SDLC/
LLC2 p ri m ary (th e SmartS witch 18 00 would be SDLC sec ondary t o the FEP) , or
logical ports (i.e., QLLC), in which case the subscriber IDs correlate to the static
routes defined in the subscriber routing tables.
PU1 Devi ces
PU1 de vi c es can n ot be defi n ed as Toke n Ring att ached t o the AS/4 00. AS/4 00 pro-
grammers might try to get around this by defining different device types (i.e., 5494/
PU 2. 0 or PU 2. 1) to 5294 and 5394 P U1 cont roller s. Howev er, when this i s done, the
ACTPU is not spoofed internally, and is sent to the remote controller. The Smart-
Switch 1800 cannot accept and respond, and the controller and AS/400 will go into
error mode. The 5394 can be RPQed to act as a PU2.1 device (see IBM RPQ
8Q0775); 5294 contr oll e rs ca n not be RPQed, and must be a t ta ched as S DL C devices ;
there are no i ssues with the 5494 , as it is a PU2 .0/2.1 node. 5294s and 5394 s can only
be directly connected to SmartSwitch 1800 devices via SDLC or X.25 with speeds up
to 64 kb ps. 549 4s can be connec ted via SDLC or frame re lay with speed s to 128 k bps,
or by To ke n Ring or Ethern e t/802.3 .
3x74s/SDLC over Frame Relay to SNA Host
Figure 3-6 Configuration Example 4
Make sure the following are configured in the local SmartSwitch 1800:
●Protocols (Chapter 5 ), to load frame relay, SNA, and LLC2, and Bridging
(required with LLC2).
●Virtual LAN ID (p age 9-1 7) , which is necessary for L LC2 functionality.
3X74
Frame
Relay Remote
SS 1800
Local
SS 1800
Host
FEP/
NCP